| 摘要: |
| 【目的】研究藏北高寒草原耐碱放线菌的多样性、产酶潜力及拮抗活性，为开发利用相关资源提供参考。【方法】从藏北高寒草原盐碱地采集22份土样，用平板稀释法从中分离放线菌，进行初步的形态鉴定后得到有代表性的36株耐碱放线菌，对这些代表性菌株的16S rRNA基因序列进行系统发育分析，将这些菌株鉴定到属；采用生长速率法测定分离菌株发酵液对1种细菌和4种农作物真菌的抑菌活性，并对分离株菌进行纤维素酶、蛋白酶、淀粉酶酶活初筛，分析其拮抗活性。【结果】从22份土样中分离到有代表性的36株耐碱放线菌；16S rRNA基因序列分析表明，这36株菌分布于放线菌门放线菌纲5个亚目5个科的5个属，即链霉菌属（Streptomyces）、糖丝菌属（Saccharothrix）、小单孢菌属（Micromonospora）、原小单孢菌属（Promicromonospora）和韩国生工菌属（Kribbella）；分离菌株中25.0%具有纤维素酶活性，8.3%具有淀粉酶活性，16.6%具有蛋白酶活性。所得耐碱放线菌中33.3%的菌株有抑菌活性，其中有5株具有高拮抗活性（抑菌圈直径≥20 mm），分别是J10、J14、J21、J48和J65。【结论】藏北高寒草原盐碱地生境蕴藏着丰富的耐碱放线菌资源，这些耐碱放线菌具有高酶和拮抗菌活性。 |
| 关键词: 耐碱放线菌 16S rRNA 生物活性 藏北高寒草原 |
| DOI： |
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| 基金项目:国家自然科学基金项目（31260005）；西藏大学农牧学院研究生创新计划项目（YJS2015-02） |
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| Biological activity and diversity of alkali tolerant actinomycetes in northern Tibet alpine grassland |
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YIN Mingyuan,HE Jianqing,ZHANG Gejie
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| Abstract: |
| 【Objective】This study analyzed biodiversity,enzymes producing potential and antagonistic activity of alkali tolerant actinomycetes to provide reference for exploration of related resources.【Method】A total of 22 soil samples were collected from saline-alkaline fields in northern Tibet Alpine grassland.Actinomycetes were isolated with plate dilution method.According to morphological characters,36 typical stains were selected.The alkali tolerant actinomycete strains were identified by sequence analysis of 16S rRNA.The antimicrobial activities of 36 strains were tested against plant pathogenic fungi and bacteria by measuring the mycelium growth rate.The activities of enzymes including amylase,proteinase and cellulase were also detected.【Result】A total of 36 representative strains were separated from 22 samples and 16S rRNA sequence analysis showed that they were grouped into 5 genera （Streptomyces,Saccharothrix,Micromonospora,Promicromonospora,Kribbella）of 5 families belong to 5 orders of actinobacteria.Among the 36 strains,25.0% could produce cellulase,8.3% could produce amylase and 16.6% could produce proteinase. Among the obtained alkali tolerant actinomycetes,33.3% showed antibacterial activity and those with high activity (diameter of inhibition zone was ≥20 mm) were J10,J14,J21,J48,and J65.【Conclusion】Diverse alkali tolerant actinomycetes with high enzyme producing activity and antagonistic activity against bacteria were discovered from saline alkaline environments in northern Tibet grassland. |
| Key words: alkali torelant actinomycete 16S rRNA biological activity northern Tibet alpine grassland |
